HOB AND METHOD FOR ASSEMBLING SUCH A HOB

Abstract

A hob comprises a hob plate, heating devices therebelow and a flat, two-dimensional carrier plate for the heating devices which runs parallel to the hob plate and has an upper face, said carrier plate bearing the heating devices on said upper face and fixedly holding said heating devices in position. Holding means are provided on the upper face of the carrier plate for each heating device. Each heating device has at least one laterally protruding holding tab, wherein each holding tab has latching means and the holding means have counter latching means for a latching connection with these latching means. The latching connection has clearance in the direction perpendicular to the surface of the carrier plate. The holding means are fastened to the upper face of the carrier plate with a releasable fastening in the direction perpendicular to the surface of the carrier plate and with a positive connection in the direction parallel to the surface of the carrier plate, wherein the holding tab runs above the carrier plate.

Claims

1. Hob comprising: a hob plate, heating devices below said hob plate, a two-dimensional carrier plate for said heating devices, wherein said carrier plate: is flat, runs parallel to said hob plate, has an upper face, bears the heating devices on said upper face and fixedly holds said heating devices in position, holding means on said upper face of said carrier plate for each said heating device, wherein: each said heating device has at least one laterally protruding holding tab, each said holding tab has latching means, said holding means have counter latching means for a latching connection with said latching means of said holding tab, said holding means are fastened to said upper face of said carrier plate with a releasable fastening in a direction perpendicular to said surface of said carrier plate and with a positive connection in a direction parallel to said surface of said carrier plate, said holding tab runs above said carrier plate.

2. The hob as claimed in claim 1, wherein each said heating device has two holding tabs, wherein said holding tabs are distributed or arranged on said heating device so as to oppose one another.

3. The hob as claimed in claim 2, wherein each said holding tabs protrude outwardly from an outer edging of said heating device.

4. The hob as claimed in claim 1, wherein said latching means are configured on said holding tabs as a latching opening with at least two latching edges, said latching edges being spaced apart and being parallel to each other.

5. The hob as claimed in claim 1, wherein said holding tab is configured to be flat and runs parallel to said surface of said carrier plate.

6. The hob as claimed in claim 1, wherein said holding means have at least one latching hook, said latching hook protruding upwardly or perpendicular to said surface of said carrier plate as counter latching means.

7. The hob as claimed in claim 6, wherein a latching bevel is configured at a top on a free end of said latching hook, wherein said latching action faces downwardly.

8. The hob as claimed in claim 7, wherein said latching hook has a latching projection facing said carrier plate, said latching hook being arranged on a free end of said latching hook, said latching hook being at a height above said carrier plate or above said holding tab, said heigh being at least twice a thickness of said holding tab.

9. The hob as claimed in claim 7, wherein two said latching hooks are provided as counter latching means, said two latching hooks being configured equally and protruding from said holding means at a distance from one another.

10. The hob as claimed in claim 1, wherein a centering projection which protrudes in a direction at right-angles from said surface of said carrier plate is configured on said holding means, wherein said centering projection extends through an opening in said holding tab.

11. The hob as claimed in claim 6, wherein a centering projection which protrudes in a direction at right-angles from said surface of said carrier plate is configured on said holding means, wherein said centering projection extends through an opening in said holding tab, wherein said centering projection is arranged between two latching hooks on said holding means.

12. The hob as claimed in claim 1, wherein said holding means have a base plate parallel to said surface of said carrier plate, said base plate bearing against the upper face of said carrier plate, wherein said base part is firmly bonded to said upper face of said carrier plate.

13. The hob as claimed in claim 12, wherein at least one fastening projection protrudes downwardly from said base plate and engages in a fastening opening being provided in said carrier plate.

14. The hob as claimed in claim 13, wherein said fastening projection does not protrude downwardly over a lower face of said carrier plate, wherein each said fastening projection does not protrude downwardly over said lower face of said carrier plate.

15. The hob as claimed in claim 13, wherein said fastening projection is elongated in a direction parallel to said surface of said carrier plate, wherein a longitudinal direction runs at right-angles to a line from a central point of said heating device to said holding tab.

16. The hob as claimed in claim 13, wherein said fastening projection protrudes at one end over said base part in a direction parallel to said surface of said carrier plate.

17. The hob as claimed in claim 13, wherein two said fastening projections of elongated shape are provided on said base part, said fastening projections being at a distance from one another, an adhesive bonding to said carrier plate being provided in said distance.

18. The hob as claimed in claim 13, wherein said fastening openings for said fastening projections are configured with a precise clearance with a clearance of a maximum of 1 mm.

19. The hob as claimed in claim 13, wherein cutaway sections or, respectively, recesses are configured in said base part at a transition between said fastening projection and said lower face of said base part in a direction perpendicular to said surface of said carrier plate.

20. The hob as claimed in claim 1, wherein a projection protrudes from said holding tab or from said base part in a direction away from said heating device in a direction parallel to said surface of said carrier plate or with a maximum length of 10 mm.

21. The hob as claimed in claim 13, wherein said carrier plate consists of metal, and said fastening openings are stamped out from said carrier plate in a stamping direction from said lower face of said carrier plate to said upper face on which said heating devices are fastened.

22. The hob as claimed in claim 1, wherein said heating devices have at least one heating element and one heating element carrier, wherein said heating element carrier has said at least one holding tab on an outer edge, wherein said holding tabs are connected in one piece and integrally to said heating element carrier.

23. A method for assembling a hob, said hob having a hob plate, heating devices below said hob plate, a two-dimensional carrier plate for said heating devices, wherein said carrier plate is flat, runs parallel to said hob plate, has an upper face, bears said heating devices on said upper face and fixedly holds said heating devices in position, and holding means on said upper face of said carrier plate for each said heating device, wherein each said heating device has at least one laterally protruding holding tab, each said holding tab has latching means, said holding means have counter latching means for a latching connection with said latching means of said holding tab, said holding means are fastened to said upper face of said carrier plate with a releasable fastening in a direction perpendicular to said surface of said carrier plate and with a positive connection in a direction parallel to said surface of said carrier plate, said holding tab runs above said carrier plate, said method having the steps: providing said carrier plate, said heating devices and said holding means, wherein an adhesive agent on said holding means for adhesively bonding said holding means to said carrier plate and said latching means is not yet activated, initially attaching said holding means to a holding tab of a heating device by latching and subsequently activating said adhesive agent and then fastening said heating device by means of said holding means to said carrier plate by adhesively bonding said holding means to said carrier plate or initially activating said adhesive agent and subsequently fastening said holding means to said carrier plate by means of adhesive bonding and then fastening said heating device by means of said holding means to said carrier plate by latching said holding tab to said holding means.

24. The method as claimed in claim 23, wherein an activation of said adhesive agent consists in a covering layer on said exposed adhesive layer of double-sided adhesive strips, which are adhesively bonded to said holding means, being removed for subsequently adhesively bonding said holding means to said upper face of said carrier plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Exemplary embodiments of the invention are shown schematically in the drawings and are described in more detail hereinafter. In the drawings:

[0035] FIG. 1 shows a section through a hob according to the invention with a hob plate, induction heating coils being pushed onto the lower face thereof and being assembled on a carrier plate,

[0036] FIG. 2 shows an oblique view from above of an induction heating coil of the hob of FIG. 1 with two lateral holding tabs, holding means being latched thereto,

[0037] FIG. 3 shows a holding means corresponding to FIG. 2 in an enlarged oblique view obliquely from above,

[0038] FIG. 4 shows a plan view of the holding means of FIG. 3,

[0039] FIG. 5 shows an oblique view from below of the holding means of FIG. 3,

[0040] FIG. 6 shows an enlarged view obliquely from above of a holding tab of FIG. 2,

[0041] FIG. 7 shows an enlargement of the right-hand holding tab of the induction heating coil of FIG. 2 with holding means latched thereon,

[0042] FIG. 8 shows a sectional view through the latching connection of the holding tab and holding means corresponding to FIG. 7,

[0043] FIG. 9 shows a side view of the arrangement of an induction heating coil corresponding to FIG. 2 with the holding tab and holding means latched thereon on a sheet metal carrier plate with a slight distance and springs therebetween,

[0044] FIG. 10 shows the arrangement of FIG. 9 in the compressed state so that the holding tab bears against the holding means,

[0045] FIG. 11 shows an oblique view of the sheet metal carrier plate with two elongated slots into which the holding means with elongated fastening rails is inserted,

[0046] FIG. 12 shows the arrangement corresponding to FIG. 7 in which the holding means is fastened to the sheet metal carrier plate in a similar manner to FIG. 11, and

[0047] FIG. 13 shows a modification of a significantly flatter holding tab in a view similar to FIG. 7 with holding means latched thereon.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0048] In FIG. 1 a hob 11 according to the invention is shown in a simplified sectional view. The hob has a hob plate 12 which may consist, for example, of glass ceramic. Fastened to a lower face 13 of the hob plate 12 is a hob housing 15 which may consist, for example, of plastics, and an operating device 17 with operating elements, for example touch-sensitive switches, and a hob controller. Moreover, the hob housing 15 has power electronics 34 which may be contained in one or two modules. A sheet metal carrier plate 30 which corresponds to the carrier plate according to the invention and which is parallel to the hob plate is provided above the power electronics 34, possibly directly placed thereon. The sheet metal carrier plate consists of aluminum with a thickness of 2 mm, wherein the thickness and material may also be modified. Induction heating coils 19 as heating devices, which are pushed upwardly in a resilient manner by means of springs 29, are arranged at the top on the sheet metal carrier plate 30. By means of the springs 29 the induction heating coils 19 are pushed with a certain force onto the lower face 13 of the hob plate 12 for a defined position, both relative to a distance from the upper face of the hob plate 12, onto which a pot to be heated is placed, and in a direction parallel to the hob plate 12 and sheet metal carrier plate 30. The holding tabs 22 according to the invention are shown in simplified form here, and relative to the holding means reference is primarily made to FIGS. 9, 10 and 12.

[0049] In FIG. 2 an induction heating coil 19 is shown from above in an oblique view, which partially corresponds to the prior art. The induction heating coil 19 has a round lower part 20 which is advantageously made of plastics and on which magnetic cores, indicated amongst other things, and thereabove the coil windings, not shown, are arranged. Toward the top the induction heating coil 19 is covered by an upper part 27 which may also consist of plastics, alternatively from heat-resistant mica. Connecting cables 28 are guided from the rear at the left.

[0050] A reinforcing region 21 on the lower part 20, which may be configured in one piece or, respectively, integrally formed thereon, may be clearly identified in FIG. 2 to the right, alternatively it may be configured as a separate part and then fastened to the lower part 20, for example adhesively bonded thereto, latched thereto or screwed thereto. The reinforcing region 21 has a considerably greater thickness than the lower part 20 itself and transitions into a holding tab 22 according to the invention which protrudes outwardly and namely parallel to the principal surface of the lower part 20 and thus also parallel to the sheet metal carrier plate 30. From FIG. 9 it may be identified that the lower face of the holding tab 22 runs slightly above the lower face of the other induction heating coil 19 and thus also of the lower part 20. This is described hereinafter in further detail. Also shown in FIG. 2 is a holding means 40 according to the invention which is latched onto the holding tab 22. This is described in more detail hereinafter.

[0051] FIG. 3 shows the holding means 40 alone in a view obliquely from above, similar to the position which is shown in FIG. 2. The holding means 40 consists of plastics and has an inherently rectangular base plate 42, for example with a thickness of 2 mm to 4 mm. Two fastening rails 44a and 44b, which correspond to the fastening projections according to the invention, protrude from a lower face of the base plate 42, as primarily the oblique view from below according to FIG. 5 shows. As may be identified from FIG. 9, they protrude downwardly approximately with the thickness of the base plate 42 or, respectively, are equally thick. The fastening rails run parallel to one another and face downwardly to form peripheral bevels for simpler insertion in corresponding openings in the sheet metal carrier plate 30. Moreover, according to the plan view according to FIG. 4 the fastening rails protrude by a few millimeters in their longitudinal direction over the base plate 42, and namely at both ends. According to FIG. 5 it may also be seen that elongated recesses 58a and 58b run at the transition from a lower face 57 of the base plate 42 to the fastening rails 44a and 44b. The elongated recesses may extend, for example, 0.5 mm to 1 mm deep into the lower face 57 and serve to receive or, respectively, to compensate for stamped edges or burrs of the openings in the sheet metal carrier plate 30.

[0052] Two identically configured projections 45a and 45b protrude from the base plate 42 on opposing sides. These projections serve for simplified handling of the holding means 40, for example even when they are already latched, according to FIG. 2, onto the induction heating coils 19 or, respectively, the holding tabs 22 thereof.

[0053] In a central region two latching hooks 47a and 47b protrude from the upper face of the base plate 42 upwardly or, respectively, are integrally formed thereon. The two latching hooks 47a and 47b have latching hook stems 51a and 51b protruding upwardly perpendicular from the base plate 42 on which the latching hooks are configured at the top with latching hook edges 48a and 48b and latching bevels 49a, and 49b at the upper end. The latching hooks face toward one another with their rear faces or, respectively, the latching hook edges 48a and 48b face away from one another. The latching hooks are located at the same height above the upper face of the base plate 42.

[0054] Exactly centrally between the latching hooks 47a and 47b, a centering projection 54 protrudes upwardly perpendicular from the base plate 42, said centering projection having an elongated cross section, see also the plan view of FIG. 4. This cross section is configured to be approximately bone-shaped, so that the centering projection 54 in the central region has a type of constriction 55 where it is narrower. This may serve the purpose that, when the latching connection is produced, the latching hooks 47a and 47b are pushed toward one another corresponding to the latching bevels 49a and 49b. Due to the constriction 55 slightly more space is present into which the latching hooks may deflect so to speak or, respectively, may be pushed further toward one another.

[0055] Advantageously, the two holding means 40 corresponding to FIG. 2, which are required in order to fasten the induction heating coil 19 to the sheet metal carrier plate 30, are identically configured. Moreover, the holding means are also mirror-symmetrical in two planes of symmetry which are perpendicular to one another and which in turn are perpendicular to the surface of the sheet metal carrier plate 30, and thus may be rotated or, respectively, latched onto the holding tabs 22 in any rotational direction. The fastening rails 44a and 44b, which in each case are of equal length, fit in all cases into the slots 31a and 31b in the sheet metal carrier plate 30, see also FIGS. 11 and 12.

[0056] FIG. 6 shows an oblique view of the holding tab 22. The holding tab has a thickness which is significantly greater than that of the base plate 42 of the holding means 40, in particular is at least double the size. This is because in spite of a large latching opening 23 the holding tab has to have sufficient stability therein. The latching opening 23 runs so to speak around the latching hooks 47a and 47b and the centering projection 54. The latching opening has opposing latching edges 24a and 24b which the latching hook edges 48a and 48b of the latching hooks 47a and 47b are latched onto or, respectively, encompass. This corresponds to a conventional latching connection.

[0057] In the direction transversely thereto two centering guide slots 25a and 25b protrude upwardly over the holding tab 22, so to speak, between which the centering projection 54 is guided with its thicker ends. This may be clearly identified in FIGS. 7 and 8. In this case a distance may be provided between the centering guide slots 25a and 25b and the centering projection 54, which may be 0.5 mm to 3 mm. Thus a certain clearance is provided between the holding tab 22 and holding means 40 when they are latched together according to FIGS. 7 and 8 or, respectively, are latched to one another. This may be clearly identified in FIGS. 7 and 8. From FIG. 8 it may also be identified that here the centering projection 54 is as high as the latching hooks 47a and 47b. The centering projection could, however, also be higher, for example in order to engage initially in the latching opening 23 and thus, when the latching connection is produced, centering the two parts with one another before the latching connection starts or, respectively, before the latching bevels 49a and 49b act or, respectively, bear at the bottom against the holding tab 22, where advantageously conventional bevels are provided.

[0058] An alternative embodiment of a holding tab is shown in FIG. 13 with the holding tab 22′ therein. This holding tab 22′ is significantly thinner, in particular even slightly thinner than the base plate 42 of the holding means 40. The holding tab protrudes from a reinforcing region 21′ which has the same relatively small thickness. The holding tab does not have a centering guide slot or the like but merely a latching opening 23′ configured in the surface of the holding tab 22′. Also here the latching edges are formed from the edges of the latching opening 23′ and the upper face of the holding tab 22′, wherein only the latching edge 24′a for the latching hook 47a may be seen here. A distance may also be identified here between the latching hooks 47a and 47b and the centering projection 54 and the edge of the latching opening 23′ which may be approximately as large as described above.

[0059] In FIG. 9, in a view similar to the sectional view of FIG. 1, it may be seen how the holding means 40 is latched from below on the induction heating coil 19 or, respectively, the holding tab 22 thereof and sufficiently far that the latching connection is produced immediately. This is why the holding means 40 protrudes sufficiently far downwardly over the holding tab 22. Springs 29, which are configured as coil springs, protrude downwardly from the lower face of the induction heating coil 19, for example to an extent of 0.5 cm to 1 cm or even up to 2 cm. Shown in dashed lines, the sheet metal carrier plate 30 is in a position if the fastening rails 44 of the holding means 40 were to be pushed into corresponding slots and the holding means 40 were to be firmly bonded. Thus it may be identified that the springs 29 would have to be already slightly pushed in, in this relative position between the holding tab 22 and holding means 40. Thus a certain amount of force is already required during assembling which, however, is simple to apply for a fitter.

[0060] In the comparable view of FIG. 10, the induction heating coil 19 is pushed to maximum extent relative to the sheet metal carrier plate 30, the springs 29 are thus compressed to a maximum extent. Advantageously, the springs are arranged in spring receivers which are configured to be slightly recessed into the lower face of the induction heating coil 19 or, respectively, into the lower part 20, so that when the spring action is maintained they no longer protrude downwardly over the lower face of the lower part 20.

[0061] From the comparison of FIGS. 9 and 10 it may also be seen that the holding means 40 now bears or, respectively, stops completely against the lower face of the holding tab 22, and the latching hooks 47a and 47b extend to the upper face of the centering guide slots 25a and 25b. FIG. 10 is able to show the installed state in the maximum compressed position. Advantageously, however, in the installed state a distance of 0.5 mm to 5 mm is provided between the lower face of the holding tab 22 and the upper face of the base plate 42 of the holding means 40 in the finished hob 11, so that the springs 29 are able to act. This is, however, variable.

[0062] In FIG. 11 it is again shown in detail how the holding means 40 with the two fastening rails 44a and 44b is inserted in corresponding slots 31a and 31b in the sheet metal carrier plate 30 as fastening openings. An adhesive bonding is produced by an adhesive layer 59 applied to the lower face 57 of the base plate 42, for example formed by double-sided adhesive tape with a certain thickness of 0.5 mm to 3 mm. Here it may also be identified that a peripheral clearance between the fastening rails 44 and the slots 31 is approximately 0.5 mm, so that the positioning may be correspondingly inaccurate. Whilst this is sufficient, at the same time a certain production tolerance is compensated and the fastening or, respectively, insertion and adhesive bonding of the holding means 40 to the sheet metal carrier plate 30 is simplified thereby.

[0063] FIG. 12, which is based on FIG. 7, in turn shows how the induction heating coil 19 is latched by means of the holding tab 22 to the holding means 40, wherein the holding means 40 corresponding to FIG. 11 is inserted and adhesively bonded to the sheet metal carrier plate 30. The adhesive bonding takes place by means of the adhesive layer 59, whereby the holding means 40 is prevented from being lifted off the sheet metal carrier plate 30. This adhesive layer 59 also substantially prevents a lateral displacement of the holding means 40 within the surface area parallel to the sheet metal carrier plate 30, so that generally the positive connection between the fastening rails 44 and the slots 31 is not necessarily required. This positive connection serves for the guidance and accuracy of the positioning of the holding means 40 during the fastening to the sheet metal carrier plate 30, and in the case of the occurrence of larger forces which exceed the adhesive action of the adhesive layers 59 or, respectively, could tear off these adhesive layers so to speak.

[0064] In an overall view of the figures it may be easily imagined how the assembling process may be carried out according to one of the two alternatives. In the first alternative, initially in each case a holding means 40 is latched, advantageously manually, onto the one holding tab 22 and then onto the other holding tab 22 of the induction heating coil 19. In this case the adhesive layer 59 on the holding means 40 is still covered or, respectively, deactivated, so to speak, in particular provided with a conventional tear-off film. Then the induction heating coil 19 is applied to the sheet metal carrier plate 30, wherein this may also involve transportation over a longer period of time and a greater distance. Shortly before fastening to the sheet metal carrier plate 30 the adhesive layer 59 is activated, in particular by tearing off the covering film, and then the induction heating coil 19 is positioned onto the sheet metal carrier plate 30 approximately in the desired position. Due to the arrangement of the adhesive layer 59 between the protruding fastening rails 44, the adhesive layer is not yet able to come into contact with the sheet metal carrier plate 30. Only when a holding means 40 with its fastening rails 44 engages, or is moved, into the corresponding slots 31 in the sheet metal carrier plate 30 does the adhesive layer 59 bear against the upper face of the sheet metal carrier plate 30 and bring about the adhesive bonding. The other holding means 40 on the other holding tab 22 of the induction heating coil 19 may also be already approximately in its dedicated position so that it is accurately pushed in the same manner with the fastening rails 44 into the slots 31 provided therefor and thus is adhesively bonded.

[0065] In the second alternative, it is provided that the two holding means 40 are initially fastened and adhesively bonded to a sheet metal carrier plate 30 by activating the adhesive layer 59. Either the induction heating coil 19 with the holding tabs 22 may be fastened or, respectively, latched thereto immediately afterwards, or alternatively in turn a transportation may be carried out over a longer period of time and a greater distance. Then an induction heating coil 19 with the holding tabs 22 is moved onto the holding means 40, and then either the latching is produced at the same time, or firstly the latching is carried out on the one holding tab 22 and then on the other holding tab 22.

[0066] Thus in the case of both alternatives the assembling may be carried out in a manner which is simple and not prone to error. In the assembled state the hob 11 is fit for purpose and robust.